Yo do realise that they'll increase the prices slowly so the price you pay for ad-free now will become ad-supported. You'll definitely be paying more than you are now to keep no ads.
That's possible. But even on a strictly short-term profit maximization kick, I don't think they raise prices that much. The premium for "ad free" has been settled by the market at about $5/mo for video streaming. They'll have to introduce their new plans at at least that below their current plan to get traction.
Once they have that $5 separation, it'll be hard to raise the prices out of sync with one another.
Once they have that $5 separation, it'll be hard to raise the prices out of sync with one another.